The exponent \(\beta \)  is usually set to a value of 2, and \(R_\chi = R_\psi \)  or \(R_n\) , where \(R_\psi \)  corresponds to wavefunction compression and \(R_n\)  to density compression. Our past experimentation with larger values of \(\beta \)  yielded negligible difference in the final outcome, though this could be investigated systematically in future efforts. The compression potentials force the wavefunction/electron density to zero at relatively large distances from the nuclei, which has been shown to improve transferability of the SK tabulations[1]}. Choice of a short wavefunction compression improves transferability by removing the overly diffuse parts of the orbitals. However, this generally comes at the expense of the accuracy of the electron density at longer distances, which can affect the description of non-covalent interactions[2]}. Hence, the standard convention is to compute the wavefunction and density compression separately, with \(R_n > R_\psi \) .
